Urinalysis Review
Dr. Mary Ann McLane

These are answers for questions used in the urinalysis review. Since you already have the questions, I will only do the answers. If you have any questions, don't hesitate to e-mail me at mclane@udel.edu. Remember that knowing why an answer is wrong is almost as important as choosing the right answer!

Clinical chemistry review answers

1. Tamm-Horsfall protein is made by the renal tubules. Bence Jones proteins are light chain synthesized by cancerous plasma cells in multiple myeloma. Creatinine is made by skeletal muscle. Urobilinogen is synthesized in the large and small intestine.

2. Least likely would be a decrease in pH, meaning an increase in acidity. It is more likely that any bacteria (as contamination or from a urinary tract infection) would convert urea into ammonia, causing the urine to become more alkaline, and thus increasing the pH.

3. Bleeding occurring in the upper GI will have been converted into many forms of degraded hemoglobin by the time the feces is excreted, and this will make the feces dark. A "red" fecal color implies fresh bleeding, with would happen if the bleed is taking place in the lower GI tract, as in the lower colon. Biliary tract obstruction would cause the feces to be pale in color since such an obstruction would prevent bilirubin from entering into the intestines, and it is this bilirubin-turned-into-urobilinogen which gives feces its brownish color. Alkaptonuria does not affect fecal color, but is one of the rare causes of urine turning black upon standing (due to elevated levels of  homogentisic acid).

4. Nitrite is not normally found in the urine, but is a metabolic product of bacterial conversion of nitrates (which are normally found in the urine from the diet).

5. The specific gravity pad of most reagent strips is sensitive to the presence of IONS. The only non-ion in the list is creatinine.

6. Seminal fluid is used to assess fertility problems. Prostate specific antigen would be used to diagnose prostate cancer. Gamma globulins would help to diagnose multiple myeloma, while uric acid is used to diagnose gouty arthritis.

7. Urobilinogen in the intestines is converted into various compounds called "urobilins", all of which collectively give feces its brown color, With no urobilinogen, the feces will appear pale or tan.

8. Only water soluble compounds will be found in the urine. The only water soluble form listed is conjugated bilirubin, also known as direct bilirubin. Free bilirubin is the same as lipid-soluble bilirubin, is the same as indirect bilirubin.

9. Ketones are the end result of fatty acid (lipid, triglyceride) metabolism, and will cause a urine specimen to be acidic in pH.

10. Most reagent strips have a glucose sensitivity of 50-100 mg/dL, while Clinitest is sensitive to 250 mg/dL reducing substances. So only "d" would react with both.

11. Red cell casts are diagnostic for glomerulonephritis.

a = squamous epithelial cells; b= transitional epithelial; c = renal epithelial; d = red blood cells; e = mucus; f = white blood cells; g = granular cast; h = cysteine crystals

12. Squamous epithelial cells are suggestive of improper specimen collection

13. The number of red blood cells present would give a moderate blood reation on the reagent strips.

14. Transitional epithelial cells line the ureters.

15. The cells normal in number are the squamous, renal and transitional epithelial cells as well as the mucus.

16. Oliguria suggests a slowing of urine flow. Casts of all kinds would be associated with that, so the answer is "g".

17. The cysteine crystals would require notification of a patient's primary care provider.

18. Nucleated cells include leukocytes and all epithelials.

19. false. Formed elements of any type will NOT affect specific gravity. Only dissolved solute will affect sg.

20. True

21. false. Squamous are 20-50 microns in size.

22. false. The renal pelvis is lined with transitional cells. Renal cells line all of the tubules (PCT, LoH, DCT, CT).

23. false. Acidity of a urine specimen has no affect on the crenation of red blood cells. If crenated rbc's are present, the specific gravity must be on the high side, causing the intracellular fluid to leave the cells.

24. true

25. true

26. false. Concentration of urine takes place in the distal convoluted tube and collecting duct, both under the influence of antidiuretic hormone.

27. true

28. false. If a specimen is initially clear, it will only become cloudy if there is a sufficient concentration of salt which will start to precipitate as the specimen cools.

29. false. An exudate is an inflammatory effusion which will have not only an increased cell count but increased protein.

30. true

31. true

32. false. lecithin = phosphatidyl choline

33. false. phospholipid... alpha fetoprotein would be measured to assess whether there is a neural tube defect.

34. false. sweat

35. true...note that "isosthenuria" means "the same specific gravity". It is the same as that of plasma, which is an abnormal thing since it shows the kidneys are unable to concentrate the urine.

36. Count all the "round" formed elements, then add a drop of 10% acetic acid under the coverslip. This will lyse the red blood cells and not affect the yeast. Go back and count the yeast, then subtract the total from this number to get an estimate of the number of red blood cells present.

37. eyepiece

38. Patients with nephrotic syndrome will excrete significantly high levels of protein, so "b"

39. Seminal fluid should have a slightly alkaline pH, so "c"

40. "Trace" on reagent strips means there's around 50-100 mg/dL glucose present, while "trace" Clinitest means there's at least 250 mg/dL reducing substance present.

41. The sensitivity of the reagent strip pad for leukocytes is about 5-10 cells per high power field, so you would expect a negative result if there's only 0-2 cells present.

42. no

43. acute glomerulonephritis. Acute cystitis (bladder infection) and pyelonephritis (upper UTI) would have more white blood cells. Nephrotic syndrome would not have red cell casts.

44. glomerular, since the protein is getting into the urine because of a problem with glomerular filtration.

45. 0-2 red cell casts per low power field

46. antibodies, which are an autoimmune reaction to the myelin sheath of nerves.

47. When you see "bacterial", think "neutrophils". Lymphocytes would predominate if the infection were viral.

48. Spinal fluid glucose will be 60-70% of plasma glucose. So a reasonable estimate would be 43 - 50 mg/dl.

49. Xanthochromia is the term used only with spinal fluid to describe any yellowish tint to the fluid. When in all three tubes, it suggests a true hemorrhage. If the color decreases or disappears from tube #1 to tube #3, it is more likely from a bloody tap.

50. hyaluronic acid. The presence of bacteria with the enzyme hyaluronidase will cause synovial fluid to have much less viscosity.

51. lungs = visceral pleura; abdominal cavity = visceral peritoneum; heart = visceral pericardium; the serous membrane farthest from the lungs would be the parietal pleura; abdominal cavity = parietal peritoneum; heart = parietal pericardium

52. amniotic fluid...all of the others should normally be clear

53 - 55. black color = upper GI bleed; excessive mucus = intestinal wall inflammation; pale color = biliary tract obstruction; red = lower GI bleed; yellow and "greasy" = steatorrhea (fat in the feces); watery = diarrhea

56. A peak at 450 nm is from bilirubin. If one had been at 410 nm, that would suggest hemoglobin's presence.

57. erythroblastosis fetalis... if the hemoglobin were present, that would suggest a blood tap.

58. Exudates will have greater than 3.0 g/dL protein, while transudates will have less than 3.0 g/dL. Exudate color will either be yellow, bloody or even green (if the infection is from Pseudomonas). Leukocyte counts in exudates are greater than 10 cells/uL. Glucose levels will be low due to its being used up by the cells present in the fluid.

59. nutrients, removal of waste, providing a cushion

60. renal clearance shows the amount of blood plasma which can be filtered by the glomerulus per unit time, therefore "a".

61. pseudoperoxidase...the property of hemoglobin used in the measurement of blood by the reagent strips. Hemoglobin's ability to transfer oxygen easily makes it act like a peroxidase to cause the oxidation of a colorless reduced chromagen into a colored oxidized one.

62. protein error of indicators...the principle used to measure protein by the reagent strips. The tetrabromphenol blue dye, stabilized at pH 3, will only change colors if protein is present.

63. inborn error of metabolism... a whole array of genetically caused illnesses which can be diagnosed through testing blood or urine: alkaptonuria, cystinuria, galactosemia, maple syrup urine disease...

64. maple syrup urine disease... an inborn error of metabolism involving the branched chain amino acids (leucine, isoleucine and valine). Their metabolic products will increase in the urine and cause a maple syrup odor

65. hemolytic disease of the newborn... caused usually from a blood type incompatability

66. hyaline membrane disease... newborn condition caused by premature delivery, before the lungs can produce a sufficient amount of surfactant (phsopholipids) to aloow proper breathing.

67. polymorphonuclear leukocyte = neutrophils = segs = polys

68. respiratory distress syndrome... same as #66

69. glomerulonephritis

note there's no #70!

71. cystitis

72. hematuria

73. isosthenuria

74. pyuria

75. erythroblastosis fetalis

76. alkaptonuria

77. multiple myeloma

78. harmonic oscillation

79. in order, top to bottom: open nueral tube defect, fetal lung maturation, cystic fibrosis, colon cancer, multiple myeloma, jaundice

80. sodium...distal convoluted tubule. Aldosterone is made by the adrenal cortex. Controlling water reabsorption  is antidiuretic hormone (vasopressin) made by the posterior pituitary.

81. Only small molecules can pass through the glomerular filter, so large proteins usually cannot. It's one reason why proteinuria is one of the earliest signs of glomerular damage.

82. Renin is produced by the juxtaglomerular apparatus (which is a combination of specialized cells in the afferent arteriole and in the distal convoluted tubule). Renin is an enzyme which converts angiotensinogen into angiotensin I. Angiotensin I goes to the lungs where specialized cells there convert it into angiotensin II, the strongest vasoconstrictor known to exist.